Hello, I'm new to the forum. I've recently bought a 240L aquarium and wanted to know how to light it. I wan't the aquarium to be low tech, with hardy fast growing plants like Hygrophila Polysperma and vallisneria spiralis. I have also purchased T5HO 2x39W to light the aquarium. This works out roughly 1 watt per 3 Litres. Will this be suffient to grow these plants? Also, any other plant recommendations would be helpful.